hi,
how can I make sure that ‘customer_student’ won’t be pushed twice to the
hash in the following example ?
@potential_course_students = []
@selected_customers.each do |customer|
customer.customer_student.each do |customer_student|
if customer_student.display_name.include?(params[:term]) &&
! @potential_course_students.include?(customer_student)
@potential_course_attendees << customer_student
end
end
end unless params[:term].blank?
appreciate any help.
Thank you
Dani
On 03 Dec 2011, at 17:22, Dani D. wrote:
end
end
end unless params[:term].blank?
Since you’re pushing objects into an array, you can just “uniq!” it:
I do have to add that you’re doing a lot in the controller that seems
to be model-related. You might want to encapsulate functionality a bit
better.
Best regards
Peter De Berdt
Peter De Berdt wrote in post #1034916:
Since you’re pushing objects into an array, you can just “uniq!” it:
Class: Array (Ruby 1.9.3)
thank you for the answer.
where should I set the “uniq!” exactly ?
rgeards
Dani
On Sat, Dec 3, 2011 at 8:22 AM, Dani D. [email protected] wrote:
how can I make sure that ‘customer_student’ won’t be pushed twice to the
hash in the following example ?
What hash?
@potential_course_students = []
@selected_customers.each do |customer|
customer.customer_student.each do |customer_student|
if customer_student.display_name.include?(params[:term]) &&
! @potential_course_students.include?(customer_student)
@potential_course_students is an empty array; how would it include
anything at that point?
@potential_course_attendees << customer_student
@potential_course_attendees isn’t defined in your snippet – ??
end
end
end unless params[:term].blank?
–
Hassan S. ------------------------ [email protected]
twitter: @hassan
Hassan S. wrote in post #1034918:
On Sat, Dec 3, 2011 at 8:22 AM, Dani D. [email protected] wrote:
how can I make sure that ‘customer_student’ won’t be pushed twice to the
hash in the following example ?
What hash?
@potential_course_students = []
@selected_customers.each do |customer|
customer.customer_student.each do |customer_student|
if customer_student.display_name.include?(params[:term]) &&
! @potential_course_students.include?(customer_student)
@potential_course_students is an empty array; how would it include
anything at that point?
@potential_course_attendees << customer_student
@potential_course_attendees isn’t defined in your snippet – ??
end
end
end unless params[:term].blank?
–
Hassan S. ------------------------ [email protected]
Hassan Schroeder | about.me
twitter: @hassan
the variable: @selected_customers includes already the potential
students. didn’t show all code.
Thanks
Dani
Hassan S. wrote in post #1034925:
On Sat, Dec 3, 2011 at 9:27 AM, Dani D. [email protected] wrote:
the variable: @selected_customers includes already the potential
students. didn’t show all code.
And I didn’t say anything about @selected_customers – I said
@potential_course_attendees isn’t defined in your snippet – ??
(among other things)
Hassan S. ------------------------ [email protected]
Hassan Schroeder | about.me
twitter: @hassan
sorry,
@potential_course_attendees should be @potential_course_students
Dani
On Sat, Dec 3, 2011 at 9:52 AM, Dani D. [email protected] wrote:
@potential_course_attendees should be @potential_course_students
So is that a typo in your email, or a typo in your code?
It does make a difference, you know 
Hint: maybe you should copy/paste instead of retyping, or use gist
(https://gist.github.com/) or equivalent if you want to preserve the
original formatting and minimize confusion.
–
Hassan S. ------------------------ [email protected]
twitter: @hassan
On Sat, Dec 3, 2011 at 9:27 AM, Dani D. [email protected] wrote:
the variable: @selected_customers includes already the potential
students. didn’t show all code.
And I didn’t say anything about @selected_customers – I said
@potential_course_attendees isn’t defined in your snippet – ??
(among other things)
Hassan S. ------------------------ [email protected]
twitter: @hassan
Hassan S. wrote in post #1034929:
On Sat, Dec 3, 2011 at 9:52 AM, Dani D. [email protected] wrote:
@potential_course_attendees should be @potential_course_students
So is that a typo in your email, or a typo in your code?
It does make a difference, you know
Hint: maybe you should copy/paste instead of retyping, or use gist
(https://gist.github.com/) or equivalent if you want to preserve the
original formatting and minimize confusion.
–
Hassan S. ------------------------ [email protected]
Hassan Schroeder | about.me
twitter: @hassan
it was a typo in the e-mail.
so how could I make sure no ‘customer_student’ gets twice into the
@potential_course_students hash.
regards
Dani
On Sat, Dec 3, 2011 at 10:19 AM, Dani D. [email protected] wrote:
it was a typo in the e-mail.
so how could I make sure no ‘customer_student’ gets twice into the
@potential_course_students hash.
-
It’s not a hash, it’s an array.
-
Do you want to prevent it being added twice or do you just want
to ensure that all customer_student instances are unique?
If the latter, then Peter’s suggestion is fine; read the Array doc
to
see how to use that method.
If the former – it’s a little more work
HTH,
Hassan S. ------------------------ [email protected]
twitter: @hassan
Hassan S. wrote in post #1034937:
- Do you want to prevent it being added twice or do you just want
to ensure that all customer_student instances are unique?
want to prevent it being added twice.
Hassan, I appreciate your help
Dani
On Sat, Dec 3, 2011 at 11:13 AM, Dani D. [email protected] wrote:
want to prevent it being added twice.
Very simplistically –
class PotentialCourseStudents < Array
def << (customer_student)
raise ArgumentError, “already exists” if
self.include?(customer_student)
self.push(customer_student)
## alternately, ignore duplicates silently
# self.push(customer_student) unless self.include?(customer_student)
end
end
Note that there are more ways to add to an array than just << so
you need to evaluate whether this is going to work for you
Also, Ruby’s stdlib has a “Set” which is an unordered collection, but
which does not allow duplicates. So if order’s not important, you could
just go with
@potential_course_students = Set.new
Something to think about…
HTH,
Hassan S. ------------------------ [email protected]
twitter: @hassan